If you say I don't believe in God --- you have not defined what it is that you don't believe .. which means you are claiming that you don't believe in nothing .. which means you believe in something
I can't say that I understand what that means after the first clause. I did define what it is that I am saying that I don't believe exists when I say that I don't have a god belief. And although I believe many things, I "believe in" nothing. That phrase implies faith to me.
seek wisdom over knowledge
Wisdom is a type of knowledge. It's knowing how to live to achieve one's ultimate goals, which is usually to be comfortable and content. Lower-level knowledge is knowing how to achieve your immediate goals, that is, knowing how the world works. The higher-level knowledge is knowing how to work those levers to achieve those ultimate goals.
That being the only way anything has ever been known, or ever will be known.
I believe that you didn't understand him. He wrote, "Of course I recognize the concept of God (and gods, and all supernatural entities). The only way in which such things are known to exist is as concepts, notions, things imagined in individual brains." What he's telling you is that gods are not known to exist, that the idea of a god has no known real referent. Compare wolves and werewolves. Both are concepts, but one has an actual referent in reality. One refers to something actual and the other to something only imagined.